Shyness as an attachment instinct:
- Frijda, N.H., et al. (1994). Social roles and functions: An interaction functions of emotion. In S. Kitayama & H. R. Markus (Eds.), Emotion and culture: Empirical studies of mutual influence (pp. 51–87). American Psychological Association.
About the activation of attachment seeking response in the presence of a stranger or in unfamiliar surroundings.
- Bowlby, R. (2007). Babies and toddlers in non-parental daycare can avoid stress and anxiety if they develop a lasting secondary attachment bond with one carer who is consistently accessible to them. Attachment & Human Development, 9(4), p. 307-319.